1. Field of the Invention
The present invention relates to a route provision apparatus, a route provision method, a navigation system, and a computer program for a computer to function as either the route provision apparatus or the navigation system.
2. Description of the Related Art
A representative mobile object for supporting various activities engaged in by a person is a vehicle, such as an automobile. And to support an operation (driving) of such a vehicle, a vehicular mounted navigation system has been developed.
According to a conventional navigation system, after a departure point and a destination point have been designated, a CPU or a map database installed in the navigation system performs a search for a route to travel to the destination, and the route and a map are displayed on a display device. Since both the route and the map are displayed, a driver can travel to the destination point without becoming lost, even when moving through an unfamiliar area.
Actually, however, once travel has begun, the route provided by a navigation system is not always followed, for a driver may veer off course and travel along a different highway. In the above case, the continued, unchanged display of the original route may not help the driver.
Therefore, a navigation system has been proposed whereby, when a vehicle veers off a route to travel and enters a different road, a search for a new route to the destination point is made from a location near the point whereat the vehicle left the original route, and the new route and a map are displayed on the display device of the navigation system (see JP-A-09-297032 (specifically on Page 5 and FIG. 2)).